2 HG5G/4G/3G/2G-V
1-20
MICRO/I Hardware Manual
2.4 External Interfaces
●
Serial Interface (COM1)
• Make sure to turn off the power to the HG5G/4G/3G/2G-V before wiring each interface or switching the
terminating resistor selector switch.
• The serial interface (COM 1) is used only for the interface of RS232C or RS422/485. Wiring both interfaces will
result in failure of the HG5G/4G/3G/2G-V. Wire only the interface used.
• The serial interface (COM2) can be used as the RS232C and RS422/485 interfaces at same time.
Interface Specification
RS232C, RS422/485
Connector
D-sub 9-pin (Plug)
Screw lock bracket
Inch Screw Thread #4-40 UNC
No.
Name
I/O
Function
Communication type
1
RDA
IN
Receive Data (+)
RS422/485
2
RD
IN
Receive Data
RS232C
3
SD
OUT
Send Data
RS232C
4
SDA
OUT
Send Data (+)
RS422/485
5
SG
-
Signal Ground
-
6
RDB
IN
Receive Data (-)
RS422/485
7
RS
OUT
Request to Send
RS232C
8
CS
IN
Clear to Send
RS232C
9
SDB
OUT
Send Data (-)
RS422/485
1
5
6
9
